Abstract

I. The crystal and molecular structure of bis-indenylruthenium
was determined by X-ray crystallographic methods. Crystals of
bis-indenylruthenium are monoclinic with four molecules per unit
cell in space group P2_(1/a). The indenyl groups are in the eclipsed
configuration, and the ruthenium atom is midway between the two
five-membered rings. Within experimental error, the molecule has
mm symmetry, and the planar indenyl groups are parallel. The
average Ru-C bond distance is 2.193 Å, but the ruthenium atom is
slightly displaced toward the carbon atoms in position 2.

II and III. The procedures as well as the results of the investigation of the crystal structures of "Ni_(5)Cd_(21)" and "Ni_(5)Zn_(21)" are described. These compounds have been believed to have crystal structures very closely related to that of γ brass. This investigation has shown that the actual atomic arrangements in these compounds are considerably more complicated than was generally assumed. The structures were found to differ drastically from that of γ brass.